Rotating-frame nuclear magnetic resonance study of the distinct dynamics of hydrogen donors in ZnO

The rotating-frame spin-lattice relaxation of two types of the hydrogen donors was well distinguished in the H-1 nuclear magnetic resonance measurements in a sol-gel prepared ZnO system, providing a unique opportunity to study the distinct proton dynamics. Our study indicates interconversion of the interstitial H (H-i). The population of the mobile H-i showed decrease above similar to 370K, apparently being trapping into the oxygen vacancies resulting in the more stable oxygen-substitutional H (H-O). The activation barrier for migration of H-i and the binding energy of H-O were found to be 0.27 eV and 0.51 eV, respectively. (C) 2013 AIP Publishing LLC.